The project includes studies on the biochemistry of hormone-sensitive adenylate cyclase in a variety of tissues. Their purpose is to explore the mechanisms by which age produces alterations of hormone-responsiveness in biological membranes, with special emphasis on the relationship between adenylate cyclase and hormone receptors. Aging in fat cells is being studied in tissue culture of preadipocytes and dedifferentiated mature fat cells (postadipocytes) from rats.